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We Thought There Was One Giraffe Species—But There Are Four

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For more than 250 years, there has been one universally accepted species of giraffe: Giraffa camelopardalis. But according to a study of the spotted giant’s DNA published today, September 8, in the journal Current Biology, that one species should actually be several.

This is exciting news, partly because it settles a debate about giraffe identity that’s been taking place for centuries. While Giraffa camelopardalis has enjoyed its seat at the top of the hierarchy since Carl Linnaeus officially described the animal back in 1758, there has been a lot of back and forth about just how many subspecies of giraffe truly exist. Some scientists believe there are 11 subspecies while most others argue there are just nine.

But it turns out they’re all wrong, according to the new study, which says there are actually four species of giraffe and five subspecies.

Axel Janke, a geneticist at Senckenberg Museum and Goethe University in Germany, said he and his coauthors were completely surprised by the findings.

“There is not much known about giraffes,” Janke tells mental_floss. In fact, the world’s tallest animals get far less scientific and conservation attention than other megafauna like lions and elephants.

To remedy this lack of knowledge, study lead author and Giraffe Conservation Fund co-founder Julian Fennessy spent six years sampling 190 giraffes from all over Central and Southern Africa. Thanks to special darts designed to snag a small tissue sample as they puncture an animal’s skin, Fennessy was able to collect noninvasive DNA samples from all nine accepted subspecies of giraffe, which Janke then analyzed against each other. The study represents the most expansive work on giraffe genetics to date.

Once the scientists started looking at the various genomes, they were surprised to find that all of their samples seemed to cluster into four distinct groups, each as different from the other as a polar bear is from a grizzly. Their analysis suggests that the giraffe family would be best described as containing four main species: the southern giraffe (Giraffa giraffa), the Masai giraffe (G. tippelskirchi), the reticulated giraffe (G. reticulata), and the northern giraffe (G. camelopardalis).

Furthermore, the study was able to eliminate some of the subspecies categories by showing that Thornicroft’s giraffe and the Masai giraffe are genetically identical, as are the Rothschild’s giraffe and the Nubian giraffe.

But this is more than some scholarly exercise in giraffe taxonomy.

“This paper is a much-needed wake-up call to save these magnificent animals,” Douglas Cavener, a Penn State geneticist who studies giraffes, tells mental_floss. (Cavener was not involved with the new study.)

Scientists estimate that there are around 90,000 giraffes left on Earth, he said. That’s a low number already—about a quarter of the number of elephants remaining, and elephants are in decline themselves. And if we can now say that there are four species of giraffes, each genetically distinct from the other and not thought to mate with each other in the wild, then the odds of any one of those species going extinct goes up quite a bit.

“With each of these four giraffe species now numbering less than 35,000, they are in peril of being lost forever by the end of this century,” Cavener says.

The good news is that a better understanding of giraffe genetics can help conservationists determine which species are in the most need of funding. For instance, now that they are recognized as their own species, northern giraffes and reticulated giraffes appear to be in particularly dire straits, with populations of just 4750 and 8700, respectively.

And there’s much work yet to be done. The scientists now want to sample every known population of giraffes in Africa to get an even better understanding of their distribution and genetics. And who knows what they’ll find.

“It’s not entirely impossible that we will find another species,” Janke says.

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Big Questions
Why Don't We Eat Turkey Tails?
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Turkey sandwiches. Turkey soup. Roasted turkey. This year, Americans will consume roughly 245 million birds, with 46 million being prepared and presented on Thanksgiving. What we don’t eat will be repurposed into leftovers.

But there’s one part of the turkey that virtually no family will have on their table: the tail.

Despite our country’s obsession with fattening, dissecting, and searing turkeys, we almost inevitably pass up the fat-infused rear portion. According to Michael Carolan, professor of sociology and associate dean for research at the College for Liberal Arts at Colorado State University, that may have something to do with how Americans have traditionally perceived turkeys. Consumption was rare prior to World War II. When the birds were readily available, there was no demand for the tail because it had never been offered in the first place.

"Tails did and do not fit into what has become our culinary fascination with white meat," Carolan tells Mental Floss. "But also from a marketing [and] processor standpoint, if the consumer was just going to throw the tail away, or will not miss it if it was omitted, [suppliers] saw an opportunity to make additional money."

Indeed, the fact that Americans didn't have a taste for tail didn't prevent the poultry industry from moving on. Tails were being routed to Pacific Island consumers in the 1950s. Rich in protein and fat—a turkey tail is really a gland that produces oil used for grooming—suppliers were able to make use of the unwanted portion. And once consumers were exposed to it, they couldn't get enough.

“By 2007,” according to Carolan, “the average Samoan was consuming more than 44 pounds of turkey tails every year.” Perhaps not coincidentally, Samoans also have alarmingly high obesity rates of 75 percent. In an effort to stave off contributing factors, importing tails to the Islands was banned from 2007 until 2013, when it was argued that doing so violated World Trade Organization rules.

With tradition going hand-in-hand with commerce, poultry suppliers don’t really have a reason to try and change domestic consumer appetites for the tails. In preparing his research into the missing treat, Carolan says he had to search high and low before finally finding a source of tails at a Whole Foods that was about to discard them. "[You] can't expect the food to be accepted if people can't even find the piece!"

Unless the meat industry mounts a major campaign to shift American tastes, Thanksgiving will once again be filled with turkeys missing one of their juicier body parts.

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10 Juicy Facts About Sea Apples

They're both gorgeous and grotesque. Sea apples, a type of marine invertebrate, have dazzling purple, yellow, and blue color schemes streaking across their bodies. But some of their habits are rather R-rated. Here’s what you should know about these weird little creatures.


The world’s oceans are home to more than 1200 species of sea cucumber. Like sand dollars and starfish, sea cucumbers are echinoderms: brainless, spineless marine animals with skin-covered shells and a complex network of internal hydraulics that enables them to get around. Sea cucumbers can thrive in a range of oceanic habitats, from Arctic depths to tropical reefs. They're a fascinating group with colorful popular names, like the “burnt hot dog sea cucumber” (Holothuria edulis) and the sea pig (Scotoplanes globosa), a scavenger that’s been described as a “living vacuum cleaner.”


Sea apples have oval-shaped bodies and belong to the genus Pseudocolochirus and genus Paracacumaria. The animals are indigenous to the western Pacific, where they can be found shuffling across the ocean floor in shallow, coastal waters. Many different types are kept in captivity, but two species, Pseudocolochirus violaceus and Pseudocolochirus axiologus, have proven especially popular with aquarium hobbyists. Both species reside along the coastlines of Australia and Southeast Asia.


Sea cucumbers, the ocean's sanitation crew, eat by swallowing plankton, algae, and sandy detritus at one end of their bodies and then expelling clean, fresh sand out their other end. Sea apples use a different technique. A ring of mucus-covered tentacles around a sea apple's mouth snares floating bits of food, popping each bit into its mouth one at a time. In the process, the tentacles are covered with a fresh coat of sticky mucus, and the whole cycle repeats.


Sea apples' waving appendages can look delicious to predatory fish, so the echinoderms minimize the risk of attracting unwanted attention by doing most of their feeding at night. When those tentacles aren’t in use, they’re retracted into the body.


The rows of yellow protuberances running along the sides of this specimen are its feet. They allow sea apples to latch onto rocks and other hard surfaces while feeding. And if one of these feet gets severed, it can grow back.


Sea apples are poisonous, but a few marine freeloaders capitalize on this very quality. Some small fish have evolved to live inside the invertebrates' digestive tracts, mooching off the sea apples' meals and using their bodies for shelter. In a gross twist of evolution, fish gain entry through the back door, an orifice called the cloaca. In addition expelling waste, the cloaca absorbs fresh oxygen, meaning that sea apples/cucumbers essentially breathe through their anuses.


Most full-grown adult sea apples are around 3 to 8 inches long, but they can make themselves look twice as big if they need to escape a threat. By pulling extra water into their bodies, some can grow to the size of a volleyball, according to Advanced Aquarist. After puffing up, they can float on the current and away from danger. Some aquarists might mistake the robust display as a sign of optimum health, but it's usually a reaction to stress.


Sea apples use their vibrant appearance to broadcast that they’re packing a dangerous toxin. But to really scare off predators, they puke up some of their own innards. When an attacker gets too close, sea apples can expel various organs through their orifices, and some simultaneously unleash a cloud of the poison holothurin. In an aquarium, the holothurin doesn’t disperse as widely as it would in the sea, and it's been known to wipe out entire fish tanks.


These invertebrates reproduce sexually; females release eggs that are later fertilized by clouds of sperm emitted by the males. As many saltwater aquarium keepers know all too well, sea apple eggs are not suitable fish snacks—because they’re poisonous. Scientists have observed that, in Pseudocolochirus violaceus at least, the eggs develop into small, barrel-shaped larvae within two weeks of fertilization.


Syzgium grande is a coastal tree native to Southeast Asia whose informal name is "sea apple." When fully grown, they can stand more than 140 feet tall. Once a year, it produces attractive clusters of fuzzy white flowers and round green fruits, perhaps prompting its comparison to an apple tree.


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